149232773SQing Zhang /* SPDX-License-Identifier: GPL-2.0 */ 249232773SQing Zhang /* 349232773SQing Zhang * Most of this ideas comes from x86. 449232773SQing Zhang * 549232773SQing Zhang * Copyright (C) 2022 Loongson Technology Corporation Limited 649232773SQing Zhang */ 749232773SQing Zhang #ifndef _ASM_UNWIND_H 849232773SQing Zhang #define _ASM_UNWIND_H 949232773SQing Zhang 1049232773SQing Zhang #include <linux/sched.h> 115bb8d344SJinyang He #include <linux/ftrace.h> 1249232773SQing Zhang 135bb8d344SJinyang He #include <asm/ptrace.h> 1449232773SQing Zhang #include <asm/stacktrace.h> 1549232773SQing Zhang 1649aef111SQing Zhang enum unwinder_type { 1749aef111SQing Zhang UNWINDER_GUESS, 1849aef111SQing Zhang UNWINDER_PROLOGUE, 1949aef111SQing Zhang }; 2049aef111SQing Zhang 2149232773SQing Zhang struct unwind_state { 2249aef111SQing Zhang char type; /* UNWINDER_XXX */ 2349232773SQing Zhang struct stack_info stack_info; 2449232773SQing Zhang struct task_struct *task; 25*dc74a9e8SJinyang He bool first, error, reset; 26a51ac524SQing Zhang int graph_idx; 2749aef111SQing Zhang unsigned long sp, pc, ra; 2849232773SQing Zhang }; 2949232773SQing Zhang 30c5ac25e0SJinyang He bool default_next_frame(struct unwind_state *state); 31c5ac25e0SJinyang He 3249232773SQing Zhang void unwind_start(struct unwind_state *state, 3349232773SQing Zhang struct task_struct *task, struct pt_regs *regs); 3449232773SQing Zhang bool unwind_next_frame(struct unwind_state *state); 3549232773SQing Zhang unsigned long unwind_get_return_address(struct unwind_state *state); 3649232773SQing Zhang 3749232773SQing Zhang static inline bool unwind_done(struct unwind_state *state) 3849232773SQing Zhang { 3949232773SQing Zhang return state->stack_info.type == STACK_TYPE_UNKNOWN; 4049232773SQing Zhang } 4149232773SQing Zhang 4249232773SQing Zhang static inline bool unwind_error(struct unwind_state *state) 4349232773SQing Zhang { 4449232773SQing Zhang return state->error; 4549232773SQing Zhang } 4649232773SQing Zhang 475bb8d344SJinyang He #define GRAPH_FAKE_OFFSET (sizeof(struct pt_regs) - offsetof(struct pt_regs, regs[1])) 485bb8d344SJinyang He 495bb8d344SJinyang He static inline unsigned long unwind_graph_addr(struct unwind_state *state, 505bb8d344SJinyang He unsigned long pc, unsigned long cfa) 515bb8d344SJinyang He { 525bb8d344SJinyang He return ftrace_graph_ret_addr(state->task, &state->graph_idx, 535bb8d344SJinyang He pc, (unsigned long *)(cfa - GRAPH_FAKE_OFFSET)); 545bb8d344SJinyang He } 55c5ac25e0SJinyang He 56c5ac25e0SJinyang He static __always_inline void __unwind_start(struct unwind_state *state, 57c5ac25e0SJinyang He struct task_struct *task, struct pt_regs *regs) 58c5ac25e0SJinyang He { 59c5ac25e0SJinyang He memset(state, 0, sizeof(*state)); 60c5ac25e0SJinyang He if (regs) { 61c5ac25e0SJinyang He state->sp = regs->regs[3]; 62c5ac25e0SJinyang He state->pc = regs->csr_era; 63c5ac25e0SJinyang He state->ra = regs->regs[1]; 64c5ac25e0SJinyang He } else if (task && task != current) { 65c5ac25e0SJinyang He state->sp = thread_saved_fp(task); 66c5ac25e0SJinyang He state->pc = thread_saved_ra(task); 67c5ac25e0SJinyang He state->ra = 0; 68c5ac25e0SJinyang He } else { 69c5ac25e0SJinyang He state->sp = (unsigned long)__builtin_frame_address(0); 70c5ac25e0SJinyang He state->pc = (unsigned long)__builtin_return_address(0); 71c5ac25e0SJinyang He state->ra = 0; 72c5ac25e0SJinyang He } 73c5ac25e0SJinyang He state->task = task; 74c5ac25e0SJinyang He get_stack_info(state->sp, state->task, &state->stack_info); 75c5ac25e0SJinyang He state->pc = unwind_graph_addr(state, state->pc, state->sp); 76c5ac25e0SJinyang He } 77c5ac25e0SJinyang He 78c5ac25e0SJinyang He static __always_inline unsigned long __unwind_get_return_address(struct unwind_state *state) 79c5ac25e0SJinyang He { 80c5ac25e0SJinyang He return unwind_done(state) ? 0 : state->pc; 81c5ac25e0SJinyang He } 8249232773SQing Zhang #endif /* _ASM_UNWIND_H */ 83